1. Field of the Disclosure
The present disclosure relates to a driving method of a fuel cell system including discharging moisture in a reformer.
2. Description of the Related Technology
A fuel cell is a device that electrochemically generates power using fuel (hydrogen or reforming gas) and oxidant (oxygen or air). That is, the fuel cell directly converts the fuel and oxidant into electrical energy by an electrochemical reaction. Fuel containing a large amount of hydrogen generated by reforming hydrocarbon-based fuel (LNG, LPG, CH3OH) or pure hydrogen is used as the fuel of the fuel cell. Air containing a large amount of oxygen or pure oxygen is used as the oxidant of the fuel cell.
Types of fuel cells include polymer electrolyte membrane fuel cells (PEMFC), direct oxidation fuel cells, and direct methanol fuel cells (DMFC). The PEMFC includes a fuel cell main body called as a stack and generates electrical energy by using the electrochemical reaction of hydrogen gas supplied from the reformer and air supplied by the operation of an air pump or a fan. The reformer serves as a fuel processing device that reforms fuel to generate hydrogen-rich reforming gas from fuel and supplies the reforming gas to the stack. To reform fuel, the fuel, together with air and water are supplied to the reformer. Water is supplied for the vapor reforming reaction of the fuel. If water used in the reforming reaction remains in the reformer, however, the water may freeze in the low-temperature environment. When water freezes, water expands and the reformer may be damaged. Further, ice blocks the passage of water and the reformer cannot be driven.